This is a five page PDF guiding you through the use of a Dallas Semiconductor DS1307 Real Time Clock chip with the AtomPro 24, 28 and 40, but not the Pro One. There's another version of this for Atoms and Nanos because of the differences in LCD command syntax. It's I2C, so only two wires are needed, and be sure to use the pullup resistors.
I make all the usual disclamers about fitness and usability for this in a commercial application. This is provided for students and aspiring hobbyists. I can't hope to anticipate every possible application or users' skill level.
There is one warning: After you copy and paste the code I provide into the Studio IDE, you'll have to perform some work on it before it will compile and program. All the quote marks and slashes (' " " ' and '/') have to be deleted and re-entered. I can't say why, nor know how to avoid it. I'm open to suggestion or explanation.
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